Conventionally, there was a vaporized-fuel processing device for an engine. In this device, a canister is provided with a vaporized-fuel inlet and with an air inlet as well as with a purge-gas outlet. The vaporized-fuel inlet is communicated with a vaporized-fuel outlet of a fuel reservoir and the air inlet is communicated with the air. Further, the purge-gas outlet is communicated with a purge-gas intake port of an intake-air passage. The vaporized-fuel within the fuel reservoir is adsorbed to an adsorbing member of the canister. While the engine is in operation, air is taken from the air-intake port into the canister with the intake-air negative pressure produced in the intake-air passage. This air separates the vaporized fuel adsorbed to the adsorbing member of the canister and the purge gas resulting from mixing the vaporized-fuel with the air is sucked from a purge-gas sucking port into the intake-air passage (for example, see Patent Literature 1).
The vaporized-fuel processing device for the engine of this type offers an advantage of inhibiting the defect that the vaporized-fuel within the fuel reservoir is sucked into the intake-air passage and is burnt within a combustion chamber to discharge the vaporized fuel into the air.
However, this conventional art arranges the purge-gas intake port intake-downstream of the throttle valve. This causes a problem.